Apparatus for making composite sheet materials



Nov. 12, 1968 J. H. LEMELSON 3,409,951

APPARATUS FOR MAKING COMPOSITE SHEET MATERIALS Filed Dec. 16, 1963 f El65a 6 b 66 65c INVENTOR. erome H.Lemelson United States Patent 3,400,961APPARATUS FOR MAKING COMPOSITE SHEET MATERIALS Jerome H. Lemelson, 85Rector St., Metuchen, NJ. 08840 Continuation-impart of application Ser.No. 589,848, May 28, 1956. This application Dec. 16, 1963, Ser. No.331,000

3 Claims. (Cl. 29-33) ABSTRACT OF THE DISCLGSURE An apparatus forfabricating composite sheet material which includes a pair of cappingsheets which are Welded together and retain a filler materialtherebetween. In one form, the apparatus is operative to continuouslyinject a filler material between two sheets of metal which are pressurewelded to shape. In another form, the apparatus continuously feedscapping sheets of plastic into abutrnent with a center sheet of foamedplastic and provides a plurality of longitudinal weld lines to securetwo sheets together.

This is a continuation-in-part of application Ser. No. 589,848, filedMay 28, 1956, for Ducted Sheet Construction, now US. Patent 3,166,829.

This invention relates to apparatus for fabricating composite sheets andpanels capable of various uses, for example, the fabrication ofcontainers, walls, heat exchangers and the like.

It is known in the art to form a sheet or plate of metal having astrip-like interfacial volume disposed between the major faces of thesheet and extending substantially parallel thereto, which volume may beexpanded by applying fluid pressure thereto to cause the metal adjacentat least one side of said strip-like volume to outwardly expand and toform a duct or tubular formation in the sheet. Two fabricationtechniques have had substantially wide commercial acceptance in thefabrication of so called ducted sheeting and are commercially referredto as the tube-in-strip and roll-bond methods. The roll-bond method isdescribed in the Long Patent No. 2,662,273 which involves printing apattern of stop-weld material on a first sheet of metal such as aluminumand hot rolling said sheet to a second sheet in a manner to weld the twotogether save in the printed areas which define said striplike volumeswhich are capable of being expanded by the application of fluid pressurethereto. The tube-in-strip method involves the incorporation of stripsof friable material into the metal billet to be rolled into sheet formwhich strips eventually define thin sheets of said friable materialwithin the final hot rolled sheeting and prevent the fusion of materialin the immediate area of the strips.

Sheet or panelling produced by the above methods has the characteristicthat the outwardly expanded portion of the sheet forming the wall of theducting is substantially reduced in cross-section and is unsupportedfrom within. Accordingly, the expanded portion of the sheet hassubstantially less strength than the sheet itself and may be easilybuckled or inwardly collapsed if subject to blows or other forcesapplied thereagainst. It is accordingly a primary object of thisinvention to provide a reinforced metal panel of improved design whichcan be produced inexpensively.

Another object is to provide an improved apparatus and method forfabricating a sheet metal panel from a unitary sheet of metal from whicha variety of improved articles of manufacture may be fabricated.

Another object is to provide an improved apparatus and method forreinforcing and stiffening a sheet of metal containing integral ductformations without the need for providing external supports therefor.

Another object is to provide a method for simultaneously expanding asheet of metal and providing internal reinforcing means therefor in asingle operation.

Another object is to provide apparatus for producing composite sheetmaterial of metal, plastic, ceramic or other compositions as well ascombinations of these materials in order to utilize to advantage theparticular characteristics of each material.

Another object is to provide an apparatus and method for producingimproxed flexible sheeting made of composite non-expanded and expandedcellular plastic materials.

Another object is to provide apparatus and improved composite sheetmaterial fabricated therefrom made of cellular nonmetallics such as hightemperature ceramics or plastics and sheet metal.

To the accomplishment of the foregoing and related ends, said inventionthen consists of means hereinafter fully described and particularlypointed out in the claims, the annexed drawing and the followingdescription setting forth in detail certain structures and methodsembodying the invention, such disclosed means constituting, however, butone of various forms in which the principle of the invention may beused.

FIG. 1 is an isometric view of a fragment of a ducted sheet materialshowing structures including a reinforcing material retained withincertain of the duct formations in the sheeting;

FIG. 1 is an end view taken in cross-section of a fragment of a ductedsheet material modified in shape of that of FIG. 1;

FIG. 2 is a side view showing apparatus operative for producing sheetmaterial of the type illustrated in FIGS. 1 and 1 on a continuous basis;

FIG. 2 is a plane view of a portion of the apparatus provided in FIG. 2;

FIG. 3 is an end view taken through plane 3 of FIG. 2 showing a portionof the apparatus thereof;

FIG. 4 is an end view in cross-section showing a modified form of theapparatus of FIGS. 2 and 3 and a modified reinforced panel;

FIG. 5 is an end view of a modified form of part of the apparatusillustrated in FIG. 2 and an internally reinforced panel material shownin cross-section and produced thereby;

FIG. 6 is an end view showing apparatus for producing a modified form ofcomposite sheet material having structural characteristics similar tothat provided in the other drawings; and

FIG. 7 shows in end cross-section a composite sheet or panel produced bymeans of apparatus of the type illustrated in FIG. 6.

Illustrated in FIG. 1 is a portion of a sheet metal panel 10 havingintegrally formed conduits or ducts 12 provided between solid formations11 of the sheet and referred to by notations 12a, 12b and 12c which areillustrated as extending substantially parallel to each other alongrespective lateral portions of the sheet. Such ducted sheeting may befabricated in accordance with the teachings of US. Patent No. 2,662,273which initially provide a sheet having one or more strip areas which arevoid of metal such as illustrated at 13 and run parallel to and betweenthe major faces of the sheet with the metal and the disposition of thestrip volumes being such that the application of sufiicient fluidpressure to said strip volume will cause the sheet material adjacentsaid strip volumes to outwardly inflate or bulge from the remainingportions of the sheet. In said Patent No. 2, 662,273, means are providedfor outwardly deforming portions of the sheet adjacent the nonweldedstrip areas thereof to extend from both of the major surfaces of thesheet. In my copending application Ser. No. 555,146, filed on Dec. 23,1955, I provide means for expanding portions of the unexpanded sheetoutward from but one surface thereof to provide formations such as 12 ofFIG. 1 by the use of a rigid platen and a deformable rubber blanketcooperating to retain one side of the panel or sheet flat whilepermitting inflation of portions of the other side of the sheet.

For the purposes of illustrating the various aspects of this invention,duct formation 12a is shown as having an interior volume 13a definedthereby and the portion 14a of the opposite wall of the sheetcomprisinng a flat wall of said ducting, as being void of any supportingmaterial other than fluid contained within said volume. Duct formation12b is shown having a solid material 16 completely filling the interiorvolume 13b of the duct. Duct formation 12c defines a volume 130 interiorthereof and the opposite wall portion of the sheet which is partiallyfilled with a material 17 lining the inside wall thereof. A sheet orpanel such as 10 may be provided in a predetermined shape and-utilized,with interiorally reinforced formations such as provided at 1211 or 12cwhich sheeting may also contain one or more duct formations such as 12awhich are void of solid fillers.

The filler materials or formations defined by the notations 16 and 17,may serve one or more of a plurality of useful purposes, the primary ofwhich is to reinforce and strengthen the panel by preventing the inwardbuckling or collapsing of portions of the outwardly expanded walls ofthe ducting filled thereby. It is obvious that, as long as the wallformations 12 which expand outward from the main body of the sheet 10,are not indented, buckled or locally damaged, the full advantage of therigidity imparted to the sheet by said formations is retained and tothis end, various low cost filler materials may be employed within saidduct formations. For example, the filler materials may comprise various,self hardenable fluid or liquid materials such as various mortars,Portland cement, ceramics, solid or cellular plastics or even metalinjected into either the preformed ducting or said interfacial stripareas, prior to solidifying, and in a manner to effect the outwarddeformation or inflation of the metal sheet to provide either formationsof the type illustrated in FIG. 1 or formations bulging from bothsurfaces of the ducted sheet 10.

A number of methods are hereinafter provided for fabricating sheeting ofthe type illustrated in FIG. 1 and articles thereof;

In a first method, the sheet of metal containing one or more slits orstrip volumes extending parallel to the major surfaces of the sheet suchas 13 illustrated in FIG. 1, is provided in a nondeformed state and aninjection nozzle is coupled to the strip volume by, for example,insertion into an opening thereto extending therefrom an edge of thesheet such as illustrated at 13'. Once coupling of said nozzle and thesealing thereof against the walls of the strip volume of the sheet iseffected and all other openings to the strip volume are sealed off, afiller material in-a fluent or liquid state is injected through thenozzle into the sheetto effect the expansion of the strip-like volumeand the outward bulging of at least one wall thereof to provide aduct-like formation such as 12 which is completely filled with the bulkfiller material such as illustrated 16. Thereafter the edge opening tothe expanded volume is closed off such as by collapsing a portion of theexpanded wall of the tubular formation or by allowing the liquid fillermaterial thereafter to solidify. Depending on the characteristics of thefiller material, the panel may be further fabricated to effect thesolidification or partial solidification of said filler material. Forexample, if the filler material requires the transfer of heat therefromto solidify, the panel may be immersed in a heat transfer liquid eitherprior to or after the injection of the filler material into the panel.

In another method, the panel may be preexpanded by means of a firstfluid and thereafter filled or at least partially filled with the corematerial in a fluent or liquid state which is thereafter allowed orcaused to solidify within the panel. Here again, closure of the end ofthe sheet tubular formation may be effected by either collapsing the endof the formation to cause the walls thereof to abut each other or byallowing the filler material to solidify. Further modifications to theabove methods may include such post operations as welding the collapsedportions of the tubular formations of the sheet to assure closurethereof and further forming of the sheet either prior to or afterexpansion of the tubular formations therein such as rolling, bending orthe like into an article of manufacture or a component of an article ofmanufacture.

The methods described hereinabove may be applied to the fabrication ofsheeting or panels of metal which may be used as components of wallpanels, containers, trays or other articles requiring an integrallystiffened sheet of metal. If the material injected to fill or partlyfill the vein-like duct formations is a self-foaming plastic capable ofsolidifying within the duct-formations 12 into a cellular material, itmay be utilized to absorb vibrations or shock forces to which the panelis subjected during use, and/ or serve as an insulating means.

FIG. 1' illustrates a structure in a ducted metal sheet of the typeprovided in FIG. 1 with the exception that both portions of the sheetadjacent the strip-like, nonfused interfacial volume 13 are permitted tobecome outwardly deformed as illustrated during the inflation process.As in the arrangements provided in FIG. 1, the outward deformation orinflation by any suitable fluid or, more preferably, by the liquidmaterial injected into said volume which eventually hardens and becomesthe supporting medium for the walls 120' and 1217 which are shown asequally outwardly deformed in FIG. 1.

In another method of fabricating a sheet structure similar to that shownin H6. 1 at 12b having a vein-like duct reinforced with a hardenedfiller material, two sheets of metal are continuously rolled together ina rolling mill with portions of either or both sheets deformed as shownat 12a to form the wall or walls of the vein-like duct in the sheetprovided when the two sheets are roll-bonded or otherwise welded into anintegral formation comprising the panel 10. Simultaneously as the sheetsare brought together and welded into an integral panel, a hardenablecore matreial of one or more of the materials described hereinabove iscontinuously injected between the sheets into the volume 13a definingconduit 12a to solidify therein as the sheet is conveyed through or fromthe rolling mill. The hardenable filler material solidifies as the sheetis conveyed if not substantially at the time the sheets are roll weldedtogether. In another procedure, the sheets comprising the finished panelmay be formed with a striplike volume such as 13' void of metal and thefiller material injected through a nozzle disposed inside or between thesheets adjacent the rolls or Welding dies to expand the sheet with theformation shown at 12b. The following variations in the fabrication suchreinforced sheet are noted:

(1) Sheet 11 is continuously formed by continuously feeding two sheetsofroll bondable metal together after at least one has been deformed byrolling or other means with one or more conduit wall formations 12a. Thesheets are continuously roll-bonded together into a unitary sheetformation by pressure welding while nozzles disposed between the sheetsand extending into the duct volumes 13a continuously inject a fillermaterial to completely fill the voids or ducts 13a, formed by thedeformed portions of the sheet(s). If the injected material is a selfexpanding material such as rigid or flexible urethane containing acatalyst to foam and expand same, the mass flow of material between thebonding or welding sheets is such that the material will be permitted toexpand into a cellular formation shortly thereafter which completelyfills the duct voids and has a predetermined cellular structure designedto impart the desired characteristics to the composite panel structure.

(II) Sheet 11 is continuously formed by continuously feeding two or moresheets of Weldable material ofthe same or different plastic, metal orceramic or combinations of two or more of these materials into a rollwelding fixture and oblique to each other prior to being brought intofacial contact and welded together. At least one of the two sheets isprovided with one or more parallel riblike corrugation such as 12atherein prior to bringing the two together. A nozzle inserted betweenthe two sheets and shaped to conform to and effect moving pressure sealwith the inside walls of the formation defining the welded ductcontinuously injects one of the hereinabove mentioned self hardenablematerials between the sheets at a constant and predetermined mass flowrate as or immediately after the two sheets are welded together, whichmaterial hardens thereafter to form a reinforcing means for the walls ofthe duct formation. If a thermosetting resin is utilized as the fillermaterial, and resistence or other form of heat generating welding meansis employed to weld the sheets together, then the heat so generated maybe utilized to at least partly if not completely cure the injected resinor the composite sheet may be radiant or induction heated.

(III) In a third procedure, sheet is continuously formed from at leasttwo sheet formations at least one of which is extruded from plastic,ceramic or metal and contains one or more formations such as 12a formedtherein to provide the wall of the duct. The sheets are fed continuouslytogether against a nozzle, mandrel or array of same inserted and heldbetween the sheets having tip portions frictionally engaged between theabutting sheets by the walls of the conduit formations so thatreinforcing material injected therethrough into the duct formations willflow continuously into the duct formations Without spillage or backflow.In other words, the tip of the nozzle(s) inserted between the weldingsheets is sealingly engaged by portions of both sheets to permit thereinforcing material to be injected under pressure without backfiow orleakage occurring.

FIG. 2 illustrates apparatus of the type described in Methods I to IIIdescribed hereinabove.

(IV) In a fourth procedure for producing a sheet 10 as illustrated inFIG. 1, the panel 11 is extruded to shape including the conduitformation 12b formed therein by extrusion and a filler material of thetype described is injected through the extrusion mandrel defining theinterior volume 13:: into said interior volume wherein it solidifies asdescribed.

(V) In a fifth procedure two sheets of roll bondable or weldable metalare continuously extruded or cast and rolled and are thereafter passedthrough a rolling mill and roll bonded together save in strip-like areascorresponding to interfacial volumes 13 of FIG. 1.

(VI) In a sixth procedure two sheets are extruded or continuously castor rolled from metal or other material one or both of which are deformedwith conduit formations such as 12a and/or 12b of FIG. 1 and arethereafter brought together in a rolling mill and roll bonded or weldedtogether along the mating flat surfaces between the said conduitformation.

In FIGS. 2 and 3 is shown apparatus for continuously producing areinforced sheet of metal containing a plurality of parallelly extendinginternally supported formations such as duct formation 12b in FIG. 1 bybringing two or more sheets together in a rolling mill, uniting same bywelding or roll-bonding and simultaneously as they are welded, injectinga fluent filler material between the sheets which solidifies intoformations such as 12b or 12b for reinforcing tubed formations of thenewly fabricated panel.

' Illustrated in FIG. 2 are two sheets of metal, plastic, ceramic orlaminates of these materials denoted 21 and 22 which are driven togetherfrom any suitable supply such as coil formations, extrusion presses,rolling or casting apparatus whereby portions of both sheets are broughtinto surface abutment and welded or otherwise bonded together in arolling mill or laminating apparatus 20 so as to have a plurality offormations or ducts provided therein and of the type illustrated inFIGS. 1 or 1'. Notations 27, 28, and 29, 30 refer to power drivenrollers which serve as guide and feed means for the sheets 21 and 22. Atleast one of the pairs of rollers, if not both, are operative to deformthe sheet fed therethrough with a plurality of corrugations of the typeillustrated at 12a of FIG. 1 and positioned so as to eventually provideduct formations in the resulting new sheet or panel which is formed inthe rolling mill 20 which are capable of being filled with a reinforcingmaterial such as the hereinabove described cellular or non-porousplastics, mortars, or the like. The rollers 23, 24 and 25, 26 arepreferably shaped to accommodate the duct formations 12 as illustratedin FIG. 3 and to simultaneously effect welding or roll bonding of thesheet formations 21 between formations 12 to provide, in effect, aso-called tubed sheet.

Disposed between the converging sheets 21 and 22 and aligned with andengaging the inside walls of the corrugated formations 12b in the sheetsare a plurality of mandrels 34 defining injection means for the fillermaterial. The nozzles or mandrels 34 are supported on a base 33 defininga header for the injection fluid which in turn is supported by a frame32 which is rigidly affixed relative to the rolling apparatus. The nose34 of each nozzle or mandrel 34 is designed so as to be compressivelyengaged by the two sheets as they are driven together and to effect aseal between the surface of the nozzle and the almost abutted or abuttedsheets. Filler material may thus be injected through an opening in theend of the nozzle under pressure without backflow and leakage. Inanother form, the sheets may be disposed downwardly and filler materialflow controlled so as to reduce or eliminate the need for effecting aseal between the nozzles and the sheets being welded together in thewelding mill 20. The nozzles may also cooperate with the rolls 23, 24 inhelping to form the sheets with corrugations or to change the shape ofthe corrugations already formed therein. In other words, if the sheets21, 22 are not already corrugated, nozzles 34 may cooperate with therolls 23, 24 in deforming either or both sheets with said duct formingcorrugations as they are fed into the rolling mill and to simultaneouslyinject filler material into the voids defined by the corrugations andthe adjacent welded portions of the sheet formed thereafter in the mill.Resistance, pressure or heat welding means may be employed to bond thetwo sheets together and the same heat conducted through the sheets maybe used to expand, cure or otherwise benefically affect the injectedfiller material. If the two sheets 21 and 22 are supplied ofthermoplastic polymers such as rigid or flexible polyvinyl chloride,polyallomer or the like, they may be heat sealed together by means ofcircular electronic heat sealing, radiofrequency dies.

FIG. 2' illustrates a portion of the header 33 and bank of injectornozzles or mandrels 34 secured thereto and laterally spaced so as to beeach aligned with a particular corrugation in the sheet 23 formed byroll-bonding the two sheets 21 and 22 together. Two nozzles 30a and 30bare shown each secured to a laterally extending header duct 33' which issupported by a plurality of longitudinal members 33 containing one ormore pipes or ducts connected to the duct in 33' to which thepassageways in the nozzles are coupled. The source of filler material islocated within or beyond the mount 32 for the header formation 33 and ispreferably controlled by means of a constant flow pump or pressurizingmeans (not shown). An automatic system may also be provided forregulating and predetermining the rate of flow of filler materialinjected into the sheet 23 by sensing the velocity of said sheet andgenerating a feed-back signal which is compared with a reference signalwhereby the difference between said feed-back signal and the referencesignal is utilized to vary the rate of flow of filler material so thatit all times remains constant with respect to the feed of sheet 23. Inturn, the roll-bonding operation may be controlled so as to beproportional to the rate of formation of sheets 22 and 23.

In FIG. 3 portions of the rolls 24 and 24' defining the first stage ofthe rolling mill are illustrated as is a portion of an injector nozzle34 shown in cross-section. The shape and function of the rolls definingthe first stage of the mill 20 will depend on the operation and degreeof rolling performed by the advanced rolls 27, 28 and/or 29, 30. Inother words, the rolls 24 and 24 may be provided primarily to conform tothe corrugations already provided in sheets 21 and 22 and to effectfilling and roll bonding the portions 23' between the corrugations orthey may additionally serve to further shape the corrugations to providea plurality of conduits of predetermined shape. In FIG. 3, portions 24aand 240 of the roll 24R are utilized to roll-bond those portions of theconverging sheets 21 and 22 adjacent the corrugations together bypressure welding the two which may be effected with or without theapplication of heat to both sheets at the rolling mill or prior to theirconvergence into the rolling mill. While the rolls 24 and 24' preferablyextend across the width of both sheets and contain a plurality ofcorrugation receiving indentations 24b at the proper lateral spacing, itmay also comprise a plurality of short roll sections as illustrated,which are spaced apart on a common shaft 248 which is supported at theside of the rolling mill and power rotated. If such short sections areutilized, roller spacing may be varied depending on the spacings betweencorrugations and the corrugated sheet and further roll-bonding of thetwo sheets is effected during their passage between the rolls, such as25, 26 situated beyond the first stage of the rolling mill.

The apparatus illustrated in FIGS. 2 to 3 may also be utilized, ifproperly modified, to produce elongated sheet metal formationscontaining one or more unexpanded strip-like volumes disposed betweenthe surfaces of the sheet such as 13 of FIG. 1. In other words, it ishereby proposed, that the injector heads 34 be disposed between two fiatsheets of metal, such as aluminum or copper, at the point where theyconverge and enter a rolling mill, as illustrated in FIG. 2, and beadapted to provide between said sheets or on the surface of at least oneof said sheets, strip-like deposits of a stop-weld material of the typedescribed in U.S. Patent 2,662,273 to prevent the eventual welding orroll-bonding of the sheets in the areas where said material isdeposited. If the nozzles are disposed as illustrated in FIG. 2immediately against both sheets where they converge and abut each otherbetween rolls 24 and 24, the tips of the nozzles would be rhodified toconverge to substantially fiat ends since the corrugations are notpresent and the material deposited from each nozzle would either beinjected under pressure between the sheets or flowed continuously ontothe surface of either sheet as it travels past the nozzle.

In a further form of the invention, the pressure of the materialinjected through the respective nozzles or mandrels of the bank 34 maybe operative to at least partially expand the corrugations in the sheetas they enter the rolling mill, provided that a fluid pressure seal ismaintained between the surface of the mandrels and the converging sheetsin cooperation with the rolls of the first stage of the mill.

The apparatus illustrated in FIGS. 2, 2' and 3 may be further modifiedto provide so called tube-in-strip material s-uch as sheet 11 of FIG. 1having one or more conduit formations such as 12a and/ or 12b providedtherein. This may be effected by providing either or both of the rollers24, 24 comprising the first stage of the rolling mill 20 made of orcovered with a compressible material such .as flexible rubber or plasticcapable of at least abutting the sheets together prior to roll bondingbut permitting inflation of one or more strip-like volumes 13" by meansof the pressure of a fluid injected through one or more nozzles such as34 illustrated in FIG. 2' and disposed between the sheets in surfaceengagement therewith as they enter said rolls. In other words, while therolls are operative to retain portions of the abutting sheets in surfaceabutment with each other, the pressure of the fluid injected through thenozzles is sufiicient to outwardly deform those portions of the sheet inalignment with said nozzles into the deformable portions of the roll orrolls. The injection fiuid may be air or a self-hardenable material asdescribed while the second stage as well as further stages of therolling mill would be shaped as illustrated in FIG. 3 or modificationsthereof to roll-bond or weld those portions of the abutted sheets whichdo not comprise walls of the conduits.

In still other forms of the invention, the rolling mill may be furthermodified to perform one or more of the following operations on thematerial passed therethrough which may comprise said two sheets or asingle extruded sheet:

(a) The rolling mill may be operative to further reduce at leastportions of the sheet or sheets fed therethrough as the material isfabricated as hereinabove described.

(b) The rolling mill may be operative to emboss the portions of eitheror both surfaces of the sheet or sheets fed therethrough.

(c) The rolling mill may be operative to form and bend portions of thesheet or sheets fed therethrough such as in the formation of angles orstructural shapes or tubing and to weld edge portions of the tubing.

(d) The rolling mill may also be operative to pierce or cut portions ofthe sheet into strips while simultaneously performing the hereinaboveoperations.

(e) The rolling mill or auxiliary apparatus downstream thereof orsituated within the mill may be operative to coat portions or the entireexterior surface of the stock treated thereby or to continuously printrepeating patterns on either or both surfaces of said material as it iscontinuously fed.

(f) The rolling mill may be operative to roll additional sheets, stripsor other shapes against either or both surfaces of the material 23 andto weld or roll bond said materials together into a unitary formation.

(g) The rolling mill or the advance set of rollers through which thelowermost of the two sheets is passed may be operative to formcorrugations therein and means may be provided such as a plurality ofnozzles to dispense a self-expanding resin into one or more of thechannels formed by the corrugations in the sheet as continuous streamsof said plastic whereafter further stages of the rolling apparatus areoperative to bring the uppermost sheet into surface abutment with thelower sheet and to bond or otherwise secure the two sheets togetherprior to complete expansion of the self-expanding or blown cellularplastic material so that after the two sheets are so joined the corematerial will expand to completely fill the Voids or channels defined bythe corrugations.

(h) For certain products to be produced from reinforced sheet materialof the types illustrated in FIGS. 1 and 1', it may be desirable toprovide said expanded or corrugated and internally filled sheet with thefilled rib formations extending along only a portion or portions of thepanels cut from said continuously formed material. This may be effectedby either collapsing the end portions of the corrugations in each lengthcut from the formed sheet to compress and/ or remove the reinforcingfiller material therefrom or by corrugating or expanding onl portions ofthe rolled sheet panel as it is fed and only filling the portions socorrugated or expanded. One of several techniques may be employedincluding shaping the rolling dies used to shape the corrugations so asto shape corrugations of predetermined length with flat portions ofsheet between corrugations which are not filled or injected with fillermaterial. Or a press such as a flying bed press or the like may beoperated to engage the surfaces of the corrugated sheet after injectingfiller material therein to compress the corrugations flat while forcingthe filler material out of the flattened sections and before it hassolidified. The sheet may then be cut by a flying cutter along thecollapsed portions or multiples thereof and may be further formed orotherwise operated on to fabricate articles or assemblies thereof.

(i) In another form of the invention, the corrugating means such asrollers 27, 28 or 29, 30 may be replaced or supplemented by rollerprinting means adapted to continuously print patterns of stop weldmaterial which repeat along predetermined lengths of the sheet to whichthey are applied and are inflatable either after the sheet 23 is cut tolengths each of which contains one or more complete patterns and/or bycontrolled positioning of one or more fluid injectors such as 34 andautomatically controlled injection of inflation fluid between the sheetsinto the roll bonded sheet formation passageways to outwardly expand thenewly formed passageway portions of the freshly roll bonded panel 23.The operation may be accomplished by the continuous or intermittentmovement of the sheet 23. In other words, sheet 23 may be stopped duringits inflation or in motion. Injection head 34 may be advanced tosealingly engage between the abutting sheets in line with a passagewayor passageways to effect inflation thereof and/ or filling with fillermaterial and retracted thereafter so as not to remove printed stop weldmaterial applied to the inside face of the sheet by said printing means.The entire process may be controlled by a multicircuit self-recyclingtimer or other suitable control means which is cyclicall operative tocontrol servos, valve actuators and other devices for preset and timedadvancing of the injectors, fluid injection and retraction thereof,movement of the sheet driving means, etc. Such automatic apparatu mayalso be operative for the controlled filling of reinforcement materialinto predetermined portions of the sheet passageways as described.

Variations in the apparatus illustrated by means of the apparatus shownin FIGS. 2 and 3 include in addition to the continuous formation ofeither or both sheets from a molten state by continuously rolling,casting and or extruding the material comprising said sheets, apparatusfor forming said sheets with corrugations provided therein to define theduct formations by extruding, casting or rolling of said formations asthe sheet itself is formed or by passing the extruded or cast sheetsthru rollers.

Composite panels may be fabricated by a modified form of the apparatusillustrated in FIGS. 2 and 3 as shown in FIGS. 4 and 5. In FIG. 4, aninternally reinforced panel 36 is provided by bringing together twosheets 37 and 41 of the desired material in a mill or welding fixtureincluding pairs of rolls 45, 46 and 47, 48 adapted to engage and weldedge formations or borders 39, 43 and 40, 44 of both sheets leavingcentral portions 38 and 42 of the sheets separated from each other andcapable of being filled as described with a bulk material. A suitablematerial for many types of panels is a self expanding plastic, metal orceramic or one which is blown into a cellular formation between thewelded sheets and solidifies immediately thereafter into a solid core 49supporting the two sheet formations in an integral and unitary panelformation. Sheets 37 and 41 may be preshaped into the illustratedflanged channel-like shapes or may be so formed by means of the rollingdies 45, 46 and 47, 48 as they are fed therethrough. Said formations 37and 41 may be freshly extruded, cast "or provided from rolls or coils,or may be integrally formed together in a single box-like formation byextrusion, into which the filler material 49 is injected through theextrusion mandrel used to define the shape of the inside wall of saidformation. Or apparatus of the type provided in FIGS. 2 and 3 may beused to form the composite panel or sheet 36 of FIG. 4 which may be madeof rigid and/or flexible materials. The illustrated flanges defined byborder portions 39 and 40 of sheet 37 and 43, 44 of sheet 41 may beretained for fastening the panel to other members or may be trimmed off.

As stated, fabrication of the panel 36 and its structure may besubjected to a number of variations including corrugating or otherwisedeforming capping sheet portions 38 and 42 and internally reinforcingsaid sheets with stiffening portions provided by extrusion or rolling ofsaid sheets or by separate extrusions, sheet formation or the like fedbetween the two sheets as they are brought together. Such internalreinforcing members may be welded or bonded to the inside surfaces ofboth sheets and extend completely or partly across the central volumedefined by the sheets.

In another form, the filler material 49 may comprise a plurality ofstrip or narrow sheet formations of expanded plastic of the typedescribed with voids between adjacent strips or may comprise rigidcellular plastic formations interposed between flexible cellular plasticformations which are simultaneously extruded or flowed between theconverging sheets 37 and 41 and completely fill the interior volumedefined by said sheets. If sheets 37 and 41 are flexible plastic, theuse of internally applied rigid and flexible formations of cellularplastic may be so applied as to impart desirable cushioning and reinforcement characteristics to the composite sheet. The rigid cellularplastic may extend as a core element or elements through the centralportion of core material 49, between the inside surfaces of sheets 37and 41 or in any suitable manner through the volume interior of thecapping sheets. Also, portions of said capping sheets may be inwardlydeformed to abut each other and welded together to form separateelongated conduit formations as shown in FIG. 5.

The filler material 49 may comprise an expanded or expanding cellularplastic material, such as polystyrene, polyethylene, polyurethyene orthe like injected between formations 38 and 42 in abutted sheets 37 and41 as described FIG. 2 and at a mass rate of flow such that saidmaterial will expand and competely fill the interior volume uponsolidification thereafter. The rolling dies 45, 46 and 47, 48 maycomprise electrical resistance and/ or pressure welding means operativeto continuously weld the flange formations of the sheets together.

In FIG. 5 is shown an apparatus of the type shown in FIGS. 1-4, modifiedto provide a plurality of parallel, internally reinforced duct-likeformation in a single panel or sheet. The arrangement may be utilized toproduce flexible as well as rigid panel formations. Two sheets 51 and 52of rigid or flexible material such as rigid or flexible formulations ofthermoplastic materials or polymers are brought together as shown inFIG. 2 over the surfaces of a plurality of injection nozzles and betweenrespective pairs of roller welding dies 54, 55; 56, 57; 58, 59.

If thermoplastic resins are employed, the dies may comprise heatedrollers or wheel type electronic sealing dies driven at the speed of thesheets to engage and weld formations 51a, 52a; 51b, 52b; 51c, 52c and51d, 52d between the corrugated formations 51' and 52' in said sheets.If, for example, sheets 51 and 52 are made of flexible polyvinylchloride or polyethylene, the injected filler material may comprisecellular or self-foaming flexible vinyl or polyethylene which areretained in the tubular duct formations or pockets formed when portionsof the sheets therebetween are heat or electronically sealed together.The dual sheets may also be replaced by a single extrusionof the same orsimilar shape, into the voids of which are injected seperate streams ofself expanding or blown cellular plastic after or during the extrusionformation of the capping sheet formation. Apparatus so provided will notrequire heat sealing dies but rollers as illustrated may be utilized toguide, drive and shape the freshly extruded, composite sheet formationuntil the expanding plastic has substantially or completely expanded toshape. Said material may be injected through the extrusion die mandrelutilized to form the interior surfaces of the duct formations.

If two sheet formations, such as the illustrated sheets 51 and 52, arefed into the laminating and welding apparatus 50 from respectiveextrusion dies or die openings in a single extruded die, they may bewelded together along strip-like formations 51a, 52a; 51b, 52b and 510,52c, etc., by the application of pressure along through the respectivepressure welding whee-l pairs 54, 55; 56, 57 and 58, 59. Or said weldingwheels may be resistance heated or may comprise respective pairs ofelectronic heat sealing dies power rotated at substantially the speed atwhich the sheets are driven through the laminating apparatus.

If the sheet formation of FIG. is extruded to the shape illustrated, thefiller material may be injected at a constant rate into the respectivevoid or conduit formations defining volumes 53 and expanded tocompletely fill out said volumes prior to solidification.

The composite panel or sheet article thus formed may be rigid orflexible depending on the materials comprising the skin or sheetformations and the filler material therefore. Typical combinations ofmaterial may include (a) flexible polymeric materials such as flexibleand expanded vinyls, polyethylene, polypropylene, polyallomer, etc., (b)rigid and flexible polymeric materials such as rigid or flexiblenonporous and cellular formulations of vinyl, urethane, polystyrene,polyethylene, etc., (c) sheet metal and rigid cellular polymericmaterials such as expanded vinyl, polystyrene, polyethylene, etc., (d)sheet metal and expanded ceramic or cellular materials such as foamedglass or other ceramics, etc., (e)

sheet metal and expanded or cellular metal, (f) sheet 7 metal filledwith non-expanded bulk material such as mortar, cement, thermoplastic orthermosetting resins.

Further variations in the laminating apparatus and methods illustratedin FIGS. 2 to 5 include the following apparatus and materialmodifications:

a) The injection heads 34' may be operative to extrude or otherwisepresent one or more formations in the shape of strips, sheets, rods orother shapes which solidify by the time they are driven between theconverging sheets and become disposed between deformed passagewayportions of the sheet or sheets and sealed therein when the sheets arewelded or bonded together. The filler material which may be continuouslyfed, may also comprise cushioning, insulation or the like fabricated ofresins, ce-

ramics, metal or the like continuously extruded from a plurality of dieopenings with the die 34 disposed sulficiently behind the convergingsheets to permit solidification of the extruding material. Since manyresinous and ceramic extrusion materials are solid or defined to shapewhen they leave the extrusion die, the multiple heads 34' may also bedisposed as shown in FIGS. 2 and 3.

(b) The reinforcing strips or formations may be metal such as formedrods or wires supplied from coils or fed, from a rolling and drawingmill in which they are continuously formed, through guide means such as34 between the sheets to become encapsulated in respective passagewaysthereof formed by corrugating the sheets as described or by deformingportions of the two sheets as they are fed into the rolling mill overthe constantly fed wires. Said fillers may also comprise single ormultiple strand wire conductors covered or coated with ceramic orplastic insulating material and fed from a coiled supply thereof ormeans for continuously forming and coating said wires, between thesheets as described to become encapsulated or embedded in the sheet 23and form a unitary panel with enclosed conductors and utilizable as awall panel for enclosures, rooms, vehicle bodies, etc.

(c) Rolls 27, 28 and 29, 30 may be operative to provide strips or layersof insulating material on respective surfaces of the aluminum (or othermetal) sheets 21 and 22 in the corrugated portions thereof or alignedwith those portions which become corrugated and dispensing apparatus 32may be operative to dispense conducting strips or feed round or flatmetal wires between the sheets aligned with opposed strips or layers ofinsulating material so as to become electrically insulated from bothsheets after said sheets are fed together and welded or roll bondedalong the portions between those containing said wires. The heads 34 andfeeding means therefore may also be modified to flow or guide a flatstrip conductor between the sheets after flowing strip-like coating ofinsulating material against each of the sheets aligned with theconductor which becomes insulated thereby from the metal of both sheetsand encapsulated within said insulation and said sheets when the sheetsare roll-bonded together in the rolling mill. In one form, theencapsulated conductors may comprise metal powder in a conductingplastic or metal powder which is melted by induction or other means asit is injected between the sheets and forms unitary conduct strips. Saidinduction means may be disposed in the injection means or the rollingmill. The sheets may be flatly roll-bonded or corrugated as described.

(d) In still another form of the invention, the members disposed betweenthe sheets may comprise resistance heating elements formed and fed byone or more of the hereinabove described means and in one or more of thedescribed forms preferably insulated from both sheets as described.

(e) In another form of the invention, the encapsulated members maycomprise a plurality of round or flat tubes of the same or differentmetal than that comprising sheets 21 and 22 which may serve as fluidconduits for flowing corrosive or pressurized material through thesheets.

FIG. 6 illustrates an apparatus for producing a portion of a compositepanel or new type of multilayer or composite sheet material. Theapparatus includes a conveyor 66 which may comprise a closed loop beltor plurality of power operated rollers for receiving, guiding anddriving a coil-fit, continuously extruded, continuously rolled orcalendared sheet of material such as metal, plastic, or ceramic beneatha plurality of laterally spaced nozzles or discharge devices referred toby the notations 64a, 64b, 640, etc., each of which are connected to acommon header 64 which feeds a fluid material to said nozzles from aninlet line 65 connected to a pressurized source of said fluid.

In a preferred form of the invention means are provided for feeding thefluid at constant rate through each of said nozzles against the uppersurface 62' of the sheet 62 as it is driven past said nozzles and isdeposited thereon as a plurality of strip-like formations 65a, 65b, 65c,etc. The material so dispatched as parallel deposits on the uppersurface 62' of 62, may be either the same or of a different formulationthan the material of which sheet 62 is made. For example, said materialmay comprise a selfexpanding or blown cellular plastic adapted to adhereto the upper surface of 62 and to provide formations, as illustrated, orformations which expand to a predetermined depth or height after theyare so deposited. Said formations may thus become insulating spacerelements for a composite sheet 63 of the type illustrated in FIG. 7which is shown having a tapping sheet 67 secured to the base sheet 62and support d by the expanded strip-like portions 65 of the depositedformations. Thus, volumes 68 between adjacent expanded formations 65contain entrapped air which may serve as insulating means and theformations 65, in addition to serving as insulating means, may also beutilized to support the two sheets apart from each other. The formations65' may be made of rigid, semirigid or flexible cellular plastic, metal,or ceramic.

Variations in the apparatus of FIG. 6 include (a) the provision ofconventional powered drive means to effect the lateral, controlledmovement of header 64 back and forth across the sheet 62' as said sheetis driven therepast to provide sinusoidal formations 65 of the spacer orexpanded material, (b) the provision of a plurality of fixtures such as64 and means for oscillating said fixture back and forth across theupper surface 62' of she t 62 so as to provide lattice-like or net-likeformations of the deposited material which are compressed in thecrossover areas when the two sheets 67 and 62 are brought together in afixture of the types illustrated in FIGS. 4 or 5. In other words, theareas of the sheets between the formations 65' may be compressiblyengaged and welded together as illustrated in FIG. 5 in a manner toprovide a panel formation of the type shown in FIG. 5 or a modificationthereof.

In another modified form of the invention, extrusion means may beemployed to provide the sheet 62 as a freshly extruded polymer and thefluid ejected from the nozzles attached to header 64 may be a blowingagent which is operative to blow or expand portions of the sheet 62intersected by said streams. The resulting formation, when the sheetportions are fully expanded, may vary from a sheet containing strip-likevolumes of nonexpanded plastic interposed between strip-like volumes ofplastic which is completely expanded to a sheet formation comprising alayer of totally nonexpanded plastic and a layer or strata of the sameplastic thereabove containing strip-like or band-like formations ofexpanded plastic which project beyond the upper surface 62' apredetermined degree and provide upper surfaces against which a secondsheet may be laminated in the manner illustrated in FIG. 7. The nozzles64a, 6417, etc., may be disposed immediately in front of the sheetingextrusion die from which sheet 62 is extruded or may comprise holes orconduits provided in the wall of the die used to extrude the sheet 62for flowing predetermined quantities of a blowing agent directly intothe freshly extruding material flowing therethrough so that, as thesheet exits from the die, strip-like portions of the upper stratathereof expand into formations of cellular plastic projecting outwardfrom the upper surface of the sheet to provide a composite cellular andnoncellular rigid or flexible sheet material.

In another form of the invention structures of the type illustrated inFIGS. 4 and 5 may be formed by providing an extruder for extruding aflexible or rigid polymeric material over a mandrel disposed within adie and means for injecting a blowing agent from the mandrel into thecentral portion of the extrusion which blowing agent is operative toonly expand the core portion of the extruding element.

It is noted that the composite assembly 63 illustrated in FIG. 7 mayalso be produced by apparatus of the type illustrated in FIG. 2 whereina plurality of injection nozzles 34 are spaced as illustrated in FIG. 2and are adapted to flow blown or self-expanding cellular plasticmaterial onto the bottom sheet 22 as the two sheets are driven togetherand passed through a modified form of the rolling mill adapted to rollbond or continuously weld border portions 67 of the upper and lowersheets together to provide the composite sheet or panel formationillustrated in FIG. 7 upon complete expansion of the formations 65'between the two.

Apparatus for fabricating an extruded article portions of which areexpanded or foamed while other portions as described remain unexpanded,may include an extruder for a solution of gas in molten plastic. If theplastic is heated as it emerges from the extruder the gas will expandforming bubbles which form cells in the plastic. Such a process has beendeveloped by R. H. Hansen of Bell Telephone Laboratories. To utilizethis process to produce partially expanded extrusions as hereinabovedescribed, only strip-like areas or portions of the extrusion are heatedby radiant energy or conduction means. The radiant energy may be derivedby conventional means for focusing or otherwise directing bands or spotsof energy such as intense light or heat against selected areas of eitheror both surfaces of the extrusion as it moves along. Suflicient heat maybe conducted to the plastic through a plurality of heated surfacesapplied to the extrusion by means of heated strip portions of the die,heated wheels or bars engaging the extrusion downstream of the die, etc.Heated bars or mandrels disposed in the throat of the extruder which mayor may not define the inside surface of the extrusion but which are insurface contact with inside or core portions of the extrusion may beused to heat internal portions of such an extrusion. If said extrusionis fabricated of a flexible polymer such as plasticized vinyl or lowdensity polyethylene, said heated devices may be operative to produce aflexible blanket of the type shown in FIG. 4 having a skin covering anda flexible foam core. They may also be utilized to produce rigid panelshaving expanded plastic cores.

Such apparatus may be operative to inject gas into the central portionof an extrusion chamber to enter the molten plastic being delivered bythe extrusion screw to the extrusion die. The apparatus is operative todissolve gas in the plastic before it reaches the die. If fine carbonblack particles are added to the solution of gas in the molten polymerand means are provided for heating the plastic as it emerges from theextruder, the plastic may be caused to expand in the plastic containingthe carbon black particles to a substantially greater degree than if theparticles are not present. The particles serve to generate hot spots orhot internal areas which heat the gas generating bubbles Within theplastic which form cells therein expanding the plastic. In other words,the hot spots permit nucleation of the bubbles within the plastic whenheated. A composite article having portions of an extrusion made ofexpanded or cellular plastic while other portions thereof are unexpandedmay thus be produced by apparatus for: (a) simultaneously extruding twoplastics into a single extrusion, one a self expanding polymer and theother a nonexpanding plastic, one inside the other or one on the otherto provide formations as described, (b) simultaneously extruding a heatexpandable plastic as described one inside of the other, one on theother or in side by side array and heating the extrusion to cause theheat expandable plastic to become cellular, (c) extruding a heatexpandable plastic as described and heating selected areas of theextrusion either as it extrudes or after it is shaped into an article tocause selected strip or band portions of the extrusion to expand.Apparatus may also be provided for forming a sheet or other formationand simultaneously thermoforming same to a predetermined shape andexpanding a portion of the thickness or stratas on either or both majorfaces thereof by means of the heat used to soften the sheet forthermoforming it to shape. The heating and expanding or forming ofselected portions of the sheet or other shape may be effected by theapplication of a heated die element to the surface, by electronic heatsealing die means which generate heat in the particles in the plasticcontaining the gas and expand the gas, by induction heating meansthrough the field of which the extrusion passes and operative toinductively heat metal or other particles in the plastic to expand thegas therein or by conduction of heat to the extrusion from the die wallsor the mandrel situated in the throat of the extrusion die. Such amandrel may be used merely to heat the core of the heat expandableextrusion to form an expanded, cellular portion of the extrusionsurrounded by nonexpanded plastic, the cross section of the expandedcore portion depending on the shape of the mandrel and the amount ofheat transferred therefrom to the extrusion. In another form, the heatedmandrel may also include means for shaping the inside wall of a tubularextrusion and for heating a portion of said wall including the insidesurface thereof to form a tube-like extrusion with a core of expandedplastic. If a second plastic is introduced through the mandrel which isnot heat expandable it may provide a nonporous interior coating on thecellular core portion. Or a wire may be fed through the mandrel to becoated by the heat expandable plastic. Induction heating means forheating the Wire maybe employed as said Wire leaves the extruder toexpand just an annular portion of the plastic covering therefore leavingthe outer layer of said plastic in an unexpanded condition.

In another form of the invention, a suitable source of radiation may beused to apply heat to a formation of heat expandable plastic through amask which mask is operative to prevent the heating and expansion ofcertain selected portions of the plastic.

The plastics defined above may be rigid or flexible formulations per seor combinations of same with each other either of which forms either theexpanded or nonexpanded portion of the extrusion. In other words, bothcellular and noncellular portions of the extrusion may be made of rigid,semirigid or flexible plastic, and the core may be flexible While thenonexpanded portions are rigid or vice versa.

Other plastic foaming or expanding apparatus which may be applied toprovide an extruded or otherwise formed article of cellular andnonexpanded portions include means for injecting blowing agents or gasinto the semimolten plastic to form bubbles therein and means forgenerating ultrasonic energy within the molten plastic to cavitate same.Such apparatus may include an injector or mandrel positioned within thethroat of the die of the type illustrated in FIG. 2 for example, toprovide an extrusion having surface, side-by-side or core portions whichare expanded or nonexpanded and adjacent portions which are expanded ornonexpanded. Thus apparatus for effecting the selective injection ofblowing agents into selected portions of an extrusion while in asemimolten or molten state or the selective injection of gas orselective cavitation of predetermined portions of an extrusion may beemployed to produce extrusions of the type described and illustrated.The extrusions include tubular formations with core and or outer layersexpanded, sheet formations with core and or outer formations made ofexpanded plastic or most any extrudable shape with one or more expandedplastic portions and one or more nonexpanded plastic portions of thesame or different polymer having the same or different formulation.

While I have shown and described preferred alternate forms of myinvnetion, it will be apparent to those skilled in the art that manychanges may be made therein without departing from the broad principlesherein disclosed. Consequently, I do not wish to be restricted to theparticular form or arrangement of parts or sequence of operations hereinshown and described, except as limited by my claims.

I claim:

1. Apparatus for making composite sheet material comprising:

(a) means for supplying a first sheet of flexible plastic material,

(b) means for supplying a second sheet of flexible plastic material,

(c) means for guiding and driving said sheets obliquely together,

(d) means supplying a third sheet made of flexible foamed plastic,

(e) means guiding and driving said foamed plastic sheet between saidfirst and second sheets,

(f) rotary welding means for receiving said first and second sheets andcompressed each against an opposite face of said foamed plastic sheetsaid welding means including means for welding parallel spaced apartband-like portions of the three abutting sheets while leaving portionsof the sheet assembly bordered by said extending longitudinally thelength thereof band-like portions bulging outwardly from the weldedportions and internally cushioned by expanded portions of said cellularplastic.

2. Apparatus for fabricating a panel made of composite materialscomprising in combination:

(a) first means forsupplying a first sheet of pressure weldable metal,

(b) second means for supplying a second sheet of pressure weldablemetal,

(0) deforming means for providing a plurality of longitudinallyextending corrugations in portions of at least one of said sheets,

(d) means for guiding and obliquely bringing said sheets together,

(e) rolling means operative to pressure weld parallel longitudinalband-like portions of the abutted sheets between said corrugations,

(f) supply means for reinforcing material in a fluent state and capableof expanding into a cellular mass, and

g) injection means coupled to said fluent material supply means, saidinjection means being disposed between said sheets and operative toinject said reinforcing material therebetween.

3. Apparatus for fabricating a ducted panel comprising:

(a) means for supplying a first sheet of material,

(b) means for supplying a second sheet of metal,

(c) means for guiding said sheets oblique to each other,

(d) means for driving said sheets together,

(e) rolling means adapted to receive said sheets and to normallycompressively roll bond said sheets across substantially their entirewidths as they are fed to provide a third sheet formation,

(-f) a supply of stop-weld material,

(g) dispensing means disposed between said sheets and coupled to saidsupply of stop-weld material, means for oscillating said dispensingmeans back and forth and operating same to dispense strips of saidstopweld material as a plurality of parallel irregular formations whichdefine irregular and parallel passageways through said roll bonded thirdsheet formation.

References Cited UNITED STATES PATENTS 2,886,930 5/1959 Martin 53-1802,898,626 8/1959 Alderfer 53-28 3,091,836 6/1963 Thomas 2933.9 2,759,3088/1956 Nawrocki 53180 3,007,848 11/1961 Stroop 53-28 RICHARD H. EANES,.TR., Primary Examiner.

